Washing machine with induction motor drive



Feb. 23, 1954 E. c. WILLIAMS 2,669,856

WASHING MACHINE WITH INDUCTION MOTOR DRIVE Filed Sept. 15, 1951 2 Sheets-Sheet 1 [N VENTUR EARL E. WILLIAMS ATTUENEY Feb. 23, 1954 E. c. WILLIAMS 2,669,856 WASHING MACHINE WITH INDUCTION MOTOR DRIVE Filed Sept. 15, 1951 2 Sheets-Sheet 2 I I A505 l/o 4i 144 I leg/46 IL is I42 //6 I 4 MM i l r A54 [NI/ENTER J 466 ,-/76 5 EARL [LWILLIAMS A T TLIIINEY Patented Feb. 23, 1954 WASHING MACHINE WITH INDUCTION MOTOR DRIVE Earl C. Williams, Syracuse, N. Y., assignor to Easy Washing Machine Corporation, Syracuse, N. Y.,

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a corporation of Dela Application September 15, 1951, Serial No. 246,759

11 Claims.

This invention relates to washing machines, and more particularly to a single tub automatically controlled oscillating agitator centrifugal type machine driven by an oscillating and rotary motor.

In an application Serial No. 206,195, filed January 16, 1951, there is disclosed a single tub washing machine having a vertical axis rotatable clothes-containing tub and an oscillatable agitator, in which the tub and agitator are driven by a motor which may oscillate or rotate depending upon the operation to be performed. In the arrangement shown, the rotor of the motor is connected to the tub and agitator through a resilient link.

The present invention is directed to improvements upon a machine of the foregoing type, and more particularly to an automatic control adapted to establish a timed sequence of operations such as washing, rinsing, and drying. The invention more particularly has to do with means for causing the motor rotor to oscillate during certain stages of the operation, and to rotate during other stages of the operation, and to time such operations with a water supply so that a complete washing, rinsing and drying cycle may be effected automatically. The means for causing the motor to oscillate or rotate are constituted by mechanically actuated electric starting circuits adapted to of the rotor or continuous rotation thereof.

The above and other novel features of the invention will appear more fully hereinafter from the following detailed description when taken in conjunction with the accompanying drawings. It is expressly understood that the drawings are employed for purposes of illustration only and are not designed as a definition of the limits of the invention, reference being had for this purpose to the appended claims.

In the drawings, wherein like reference characters indicate like parts:

Figure 1 is a vertical section taken through a washing machine of the type referred to;

Figure 2 is a circuit diagram adapted to establish continuous rotation of the rotor, the mechanical elements of which are shown in section, and taken on the section line 2-2 of Figure 1;

Figure 3 is a circuit diagram adapted to establish oscillatory drive of the motor;

Figure 4 is a timer controlled circuit diagram including the circuits of Figures 2 and 3, and other controls essential to a washing cycle;

Figure 5 is a time diagram illustrating the sequence of operation of the by the timer control; and

initiate either oscillation switches actuated Figure 6 is an alternative circuit diagram to that shown in Figure 2, for establishing continuous rotation.

Referring to Figure 1, there is shown a washing machine having a surrounding casing Ill including a base l2, within which is a stationary drain tub l4 resting on an annular platform I6. Within the drain tub is positioned a laundry-containing centrifuge tub l8 and an oscillatable agitator 20. Within the base l2, there is mounted a motor having a stator frame 20 supported from the bottom 28 of the tub M, such stator frame having an internally threaded collar 22 from which there extends upwardly a central tubular column 24, such column projecting through the tub I 4. A. jam nut 26, threaded upon the column 24 above the bottom 28 of the tub I4, is adapted to clamp through the column 24 the motor stator 20, and more particularly its collar 22, against the tub bottom 28.

In the arrangement shown, the tub I4 is provided with a drain outlet 30 continuously open.

Within the stator frame 20 is a rotor 32 mounted on a vertical shaft 34 journaled in stator bearings 36 and 38, the lower end of the shaft resting upon a ball thrust bearing 40. Such shaft at its upper end is connected to the lower end of a resilient link 42 extending upwardly through the tubular column 24. Such resilient link, in the form shown, consists of an elongated cylindrical member of rubber or rubber-like material having substantial torsional resiliency.

The upper end of the rubber link 42 is drivably connected through a hollow stub shaft 44 to the central column 46 of the tub it, such central column being journaled upon the tubular column 24 as at 48 and 5D, the latter bearing being a thrust bearing. The stub shaft 44 is journaled in a bearing sleeve 52 mounted in the upper end of the column 24, and for disassembly purposes, such shaft has a splined connection 54 to the inwardly directed flange 56 of the tub column 46.

The upper end of th resilient link i2 is provided with a bore 58 through which extends a shaft (it, such shaft terminating at its lower end in a head 62 which is bonded to the upper and lower portions 64 and 65 of the resilient member 42. The shaft fill extends through the hollow stub shaft it, and is drivably connected to an outer agitator sleeve 63 rotatably mounted upon the tub column 46, the shaft being keyed to the :agi tater column 68 by means of the squared end Ill engaging a similar contoured aperture in the inwardly directed flange 12 at the upper end of the agitator sleeve. The flange '12 may bear on the flange 58 through a thrust washer l4 and is held in position on the end of the shaft 60 by the knob It, the latter having threaded engagement with the end of the shaft 60. It will be understood that the resilient link 42 is bonded at its opposite ends to a drive collar '18 at the lower end and the head 80 formed integral with the hollow stub shaft 44. The apparatus thus far described is essentially the same as that disclosed in the aforementioned application Serial No. 206,195, and in such application, an alternative construction employing coil torsion springs is also shown.

The outer circular wall 82 of the centrifuge tub i8 is outwardly and upwardly tapered, and provided with a rolled edge 84 and a plurality of apertures t6 adjacent thereto located above the normal water line within the tub I 8.

The motor may be of the single phase induc tion type in which the rotor may turn in either direction, depending upon the initial direction of rotation. In the arrangement shown, rotation of the rotor 'inay be initiated in one direction, which will result in torsionally stressing the resilient linl: 42. Th initial rotation will b atrested when the torsion is sufficient to stall the rotor. The stored energy in the resilient link thereupon initiates rotation of the rotor in the opposite direction, which rotation is again stalled when the resilient link is torsicnally stressed in anamount to cause stalling. The rotor thus pcriodically oscillates. The weight of the tub 18 with the laundry and wash water contained therein acts as a reaction or movable anchor by reason of its coupling to the upper end of the resilient link 52, and while th tub may angularly move through a few degrees in opposition to the rotation of the motor rotor, the inertia of the tub and the water contained therein is relatively great compared to that of the rotor, 0 that the rotor may turn through several revolutions while the tub merely rotates through a few degrees. Agitation is effected by reason of the connection of the'agitator sleeve to the torsional member 42 at a point spaced from. the upper end thereof, such agitator being connected to the torsional member by the head 62 which divides the torsional member into the upper portion 64 and the lower portion 66. Thus, as the rotor oscillate to and fro through several revolutions, the agitator will be caused to oscillate to a lesser extent, for example in the order of 180.

When it is desired to centrifugally extract wash water or rinse water from laundry contained within the tub 3, it is merely necessary to convert the oscillatory motion to continuous rotation by biasing the torque on the motor rotor in one direction, so that each oscillation includes a greater movement in one direction than in the other. After a series of biased oscillations, the rotor establishes rotation in a continuous direction. Upon increase in speed, water is caused to rise along the outwardly tapered wall 82 for discharge through portsBB.

Located in the base of the casing is a hot and cold water mixing valve 82 controlled by solenoids Mand'flii for the hot and cold water, respectively. Th mixing valve 82 is supplied by hot and cold water inlet pipes 88 and 90, respectively, and the outflow from the valve is led to a discharge nozzle 92 overhanging the tub 18. Such nozzle may be angularly directed toward the center of the tub It, so that while the tub I8 is spinning, the water jet may be broken up by the agitator vanes 20 and caused to be discharged'over laundry compacted against the side wall .18 to effect a centrifugal rinse. The conduit 84 leading'to clockwise direction.

th discharge nozzle 92 has preferably interposed therein, means (not shown) for efiecting a constant rate of flow, so that by operating th mixing valve 82 to allow flow of water therethrough for a specified time, the quantity of water dolivered to the tub I8 can be selected, regardless of line pressure variations, or whether one or both valves are operated. A common device for this purpose is disclosed in British Patent No. 372,286, or Halenza 2,500,750.

Within the motor casing 20, there is provided a split friction collar 96 riding on the lower end of the rotor shaft 34. Such collar, as shown in Figure 2 or 6, has light frictional contact with the shaft 3d, so as to tend to turn with the shaft unless obstructed. The collar has a spring loop 98 which acts as a switch operating arm, as well asan arm for engaging the fixed stop I00. When the shaft 34 rotates in a clockwise direction as shown in Figure 2, rotation of the collar is stopped by engagement of the arm 98 with the stop 100-. When the arm Sii rotates in a counterclockwise direction in response to counterclockwise rotation of shaft 34, the arm engages a spring contact finger m2 and is effective to open the contacts I04. The movement of the spring contact M12 is limited by an additional stop 106. The mechanism thus described is utilized in a circuit to cause oscillatory drive of the rotor to change to continuous rotation, the circuit for which is shown in Figure 2.

As previously pointed out, the rotor of the motor, when started in either direction, torsionally stresses the resilient drive link 42, causing the same to stall and initiate reverse rotation of the rotor, whereby oscillatory motion of the armature is established. For such operation, the field winding of the stator M8 is in circuit across the line and the starting winding is removed from the circuit, and the switch -I I0 is in the right hand position to effect such result. After a washing period has been completed and it is desired to cause the tub l8 to rotate to centrifugally remove the wash water therefrom and extract the wash water from the clothes centrifugally, the motor is caused to discontinue the oscillatory drive and operate as an ordinary motor rotating continuously in one direction. To effectuate this result, the switch l H) is shifted to the left hand position, whereby the starting winding H2 and the starting capacitor H4 are thrown in parallel circuit with the field winding 198, such circuit, however, being opened and closed by the contacts 104. The starting winding is so related to the field as to effect starting in a counterclockwise direction, as shown in Figure 2.

It will be seen that when the starting winding circuit is thus connected in parallel with the field, the contacts HM will be closed during rotation of the shaft 34 in the clockwise direction and open during rotation in the opposite direction. Thus, the starting winding will be effective to strongly resist rotation of the rotor in a This has the effect of severely decreasing the angle through which the armature rotates clockwise urging counterclockwise rotation. The motor rotor will thus be stalled quickly, forcing the resilient link to re lieve its torsion by rotating the basket in the desired direction through a much greater angle than during oscillation. Before several cycles of attempted oscillation .have' occurred, continuous rotation has been efiected in a counterclockwise direction. In a GO-cycle motor, having .8 poles,

the rotation speed will increase to approximately- 860 R. P. M

The acceleration of the tub I8 first causes the wash water to spill through the apertures 66 and even over the rim 84, carrying the surface scum to be centrifugally removed from the tub. Thereafter, as the speed increases, further water is wrung from the tub by centrifugal force as in ordinary centrifugal extraction. Thus, it will appear that by the mere parallel connection of the starting winding as controlled by the contacts I04, oscillatory motion is converted to rotary motion. Once rotation has been established, the starting Winding circuit is held open by the friction arm 06 which holds the contacts I04 open.

While as described in the above referred-to application, oscillatory motion of the motor may be started by manually rotating the tub I0 through a few degrees, automatic starting is provided by an impulse switch, such switch being shown in the base of the casing at H6. Such switch is shown in detail in Figure 3, and comprises a solenoid H8 having a, plunger I carrying a spring finger I22. The plunger is normally held in the position shown by the biasing spring I24 connecting the plunger resiliently to the solenoid frame I26. Mounted on the frame are a pair of contact fingers I26 and I30, having normally open contacts I32. The finger I30 has an insulated projection I 3I extending into the path of movement of the finger I22, so that when the solenoid I I8 is energized, the finger $22, in passing over the projection I3 I, causes the finger I30 to close the contacts I32 momentarily. The abutment I63 holds the finger I30 against any accidental movement tending to close contacts upon the return of the plunger. Such contacts are in circuit with the starting winding H2 and capacitor I14. In the circuit of Figure 3, closing the switch I34 energizes the stator field I06 and at the same time energizes the solenoid I I6. This in turn causes the plunger I20 to move to the left momentarily closing the contacts I32 through the starting winding circuit. The momentary passage of current through the starting winding circuit causes the rotor of the motor to move a few degrees against the torsion of the resilient link 42, whereupon the oscillatory movement'of the rotor commences. The initial oscillations are of relatively low amplitude, but the amplitude rapidly increases to the maximum required for providing a sufficient angular movement of the agitator 20.

Automatic control of the washing machine is eifected through a timer I 36 which may be of the usual. multiple cam type, such cams sequentially actuating electrical contacts to make and break at prescribed intervals the various circuits essential to performing a washing, rinsing and drying sequence. There is also provided a manual switch actuating control for selecting hot or lukewarm water, the latter being a mixture of cold and hot, as indicated at I36, and a further switch actuating control I46 for selecting the quantity of water used for washing, such quantity being selected in accordance with the size of the laundry load to be washed.

In Figure there is shown a circuit diagram incorporating the switches actuated by the controls I36 and I40, and the timer I36 and its cams, as well as the switches requiring actuation described in connection with the circuit of Figure 2 for changing from oscillatory motionto rotary motion and the circuit of Figure B -for initiating the oscillatory motion. In the circuit diagram of Figure 4, the timer motor I421 actuates cams adapted to close contacts I44, I34, I46; H0, and I48, as well as contacts I50. The se' tacts I46, I 50 and I48 are closed. The duration of closure of contacts I46 is indicated by the length of the elevated portion I56 of line I58, and the time during which contacts I50 are closed is indicated by the elevated portion I60 of the line I62. Likewise, the duration of the time contacts I48 are closed is indicated by the length of the elevated portion I64 of line I66.

The contacts I46 and I50 and I48 are connected to a selector switch, indicated on Figure'4 as I40, such switch being actuated by the previously referred-to control I40. By placing the contacts I46 or I50 or I48 in circuit with the hot and cold solenoids 84 and 86, the time such solenoids operate to open the valve 82 to admit water to the tub l8 may be varied, by reason of the diiference in lengths of the cams as indicated on the time diagram at I56, I60 and I64. At the same time, whether warm water or hot water is utilized depends upon whether the switch indicated at I38 on Figure 4 is closed or open, such switch I38 being actuated by the manual control also indicated by the reference character I38.

After the lapse of sufficient time to substantially'fill the tub I 8, the motor circuit contacts I34 are closed by its cam, the length of time being indicated by the elevated portion I66 of the line I68 in Figure 5. Upon the closure of the contacts I34, which in eifect performs the function of the switch I 34 in the circuit shown in Figure 3, the solenoid I I8 is energized as Well as the field I08, and the contacts I32 are momentarily closed, energizing the starting winding II 2 through the starting capacitor I I4. Oscillation of the motor rotor thus commences. The oscillation of the motor rotor causes the agitator 20 to oscillate while the tub I6 and its contents act to anchor the upper end of the resilient link 42. Toward the end of the period indicated by the elevated portion I66, during which the motor field is energized, it is desirable to remove the wash water from the tub I8, a suflicient washing period having elapsed. For this purpose, the cam, formerly operating to close contacts I50, now closes contacts I I0, as indicated by the depressed portion I69 on line I62, thereby establishing the circuit shown in Figure 2Tthrough the starting winding, the starting winding being energized during rotation of the rotor in one direction, and having the braking effect previouslyreferred to. The oscillatory motion is converted to continuous rotation. The contacts I I0 remain closed during spinning, so that if a power failure occurs, upon re-establishment of power, the conditions required for starting are present. If stoppage occurred with contacts 504 closed, a starting kick immediately results. Otherwise, solenoid actuating contacts I62 are momentarily closed; thus assuring starting an oscillation. which oscillatory motion is promptly converted to spinning by the unidirectional switch of Figure2. l

2 Upon the completion of the period c! time represented by the elevated portion I86 of linerIGB, the field circuit of the motor is opened, the wash water formerly contained within the-tub will have been removed by centrifugal force, and the tub I8 will come to rest. While retarding, rinse water may be introduced into the tub, the quantity thereof varying in accordance with the wash load as previously, so that the quantity of wash water introduced depends upon the length of timethe elevated portion I10 of line I58, or the elevated portion I12 of line IE2, or the elevated portion I14 of line I56, holds the respective contacts I46, I50, and I48 closed, it being understood that only one of these contacts will be in circuit by reason of the selector switch I40.

When the tub has had opportunity to partially fill, the motor field is again energized for a pcri-od of time as indicated by the elevated portion I16 of line I68. The motor in the manner previously described thus commences its, oscillatory drive,- thus effecting an agitated rinse. After such rinse has continued for a period, the con-v tacts' H are again closed as is indicated by the depressed portion I18 of line I62, whereupon the oscillatory drive is converted to a rotary drive and the rinse water is centrifugally discharged from the tub I8. After the rinse water is eliminated from the tub, a spray rinse period commences. Such spray rinse period continues for a. period of time as indicated by the elevated portions I80 of the line I58, or I82 of the line I62, or the elevated portion I84 of the line I86, again depending upon-which circuit has been selected by the switch I40. It will be seen that the nozzle 1 92, being directed toward the central portion of the'tub, will direct the stream of water toward the rotating agitator 20. Since the tub will'be spinning at a speed of 860 R. P. M., the blades ofthe agitator will interrupt such stream, diffusing the water within the tub I850 as, to evenly distribute the same upon the mass of laundry compacted centrifugally upon the side wall 82 of the tub I8. The spray rinse water will continue to flow for the period as indicated, and after the flow is discontinued, the tub will continue to rotateat centrifuge speed to extract the water and damp dry the laundry. The timer motor will continue the operation of the cam until the motor contact I34 is open, whereupon the tub I8 decelerates and the cycle is complete.

In Figure 6, an alternative circuit is shown for converting oscillatory motion to rotary motion without using a starting winding. In the form shown, upon opening switch II I, the contacts I04 merely open the stator field circuit upon rotation in one direction. This biases the oscillations sufiiciently to cause conversion to rotary'motion.

While various embodiments of the invention have been illustrated and described; it is to be understood that the invention is not limited thereto. As various changes in the construction andarrangement may be made without departing from the spirit of the invention, as will be apparent to those skilled in the art, reference will be had to theappended claims for a definition of the limits of the invention.

What is claimed is:

1. A washing machine comprising, in combination, a centrifuging tub, an oscillatable agitator concentrically arranged therein and rotatable relative thereto, a, reversible induction motor, .a resilient coupling 'having'its ends connected between said motor and tub,- means. driv ably connecting said agitator to said coupling B at. a point intermediate the 'ends thereof, and means for converting oscillatory rotation of'said motor 'to continuous rotation thereof.

2. A washing machine comprising, in combination, a centrifuging tub, an oscillatable agitator concentrically arranged therein and rotatable relative thereto, a reversible induction motor, a resilient coupling having its ends connected between said motor and tub, means drivably connecting said agitator to said coupling at a point intermediate the ends thereof, means for initially establishing rotation of said motor, and means for converting oscillatory rotation of said motor to continuous rotation thereof.

3. A washing machine comprising, in combination, a base, an upstanding tubular'sleeveprojecting therefrom, a reversible motor in said'base having its rotor arranged coaxially with respect to and below said sleeve, .a centrifuging tub journaled on said sleeve, an oscillatable agitator rotatable relative to said tub and therewithin', a resilient connecting link between said'tub and rotor extending through said sleeve, a driving connection between said agitator and a point intermediate the ends of said resilient link, a stator flux producing winding in said motor, and a unidirectional switch actuated by rotor-rotation in circuit with said winding to break the circuit upon rotation in one direction.

4. A washing'machine comprising, in combination, a base, an upstanding tubular sleeve projecting therefrom, a reversible motor in said base having its rotor arranged coaxially with respect to and below said sleeve, a centrifuging tub journaled on said sleeve, an oscillatable agitator rotatable relative to said tub and therewithin, a resilient connecting link between said tub and rotor extending through said sleevea driving connection between said agitator anda point intermediate the ends of said resilient link, a stator flux producing winding in said motor, a unidirectional switch actuated by rotor rota-- tion adapted to be'placed in circuit with said winding to break th current flow in said winding upon rotation in one direction, and time controlled means for rendering said circuit effective to control current flow in said winding. 1

5. 'A washing machine comprising, in combi-'- nation, a centrifuging tub, an oscillatable agitator concentrically arranged therein and rotatable relative thereto, a reversible induction motor, a. resilient coupling having its ends con nected between said motor and tub, means drivably connecting said agitator to said coupling at a point intermediate the ends thereof, means for converting oscillatory rotation of said motor to continuous rotation thereof; means for 'sup plying wash water to said tub, means for draining" centrifuged liquid discharged from said tub, and time controlled means actuating said supply means, and subsequently renderingsaid converting means effective to establish continuousrotation.

6. A washing machine comprising, in combination, a centrifuging tub, an oscillatable agitator concentrically arranged therein and rotatable relative thereto, a reversible induction motor, a resilient coupling having its ends connected between said motor and tub, means drivably connecting said agitator to said coupling at a point intermediate the ends thereof, means for initially establishing rotation of said motor, means for converting osoi-llatoryrotation of said motor to continuous rotation thereof, means for supplying wash water to .saidtub, means-"for draining centrifugal liquid discharged from said tub, and time controlled means for sequentially activating said supply means, said initial rotation establishing means, and said converting means effective to establish continuous rotation '7. In an oscillating drive, a rotatable device having inertia resistance to rotation, an induction motor having a field winding, a starting winding, and a rotor, the latter rotatable in either direction with substantially equal torques for any given speed when said field winding only is energized, the direction of rotation depending on the direction of initial rotation, a torsionally resilient link connecting said rotor to said inertia device and normally maintaining opposed oscillatory movement of said device and rotor when said field winding alone is energized for driving said device, means for closing a circuit to said field winding, and means energized by the closing of said circuit independent of motor rotation to momentarily close a circuit through said starting winding to momentarily create a starting torque in one direction.

8. In an oscillating drive, a rotatable device having inertia resistance to rotation, an induction motor having a field winding, a starting winding and a rotor, the latter rotatable in either direction with substantially equal torques for any given speed when said field Winding only is energized, the direction of rotation depending on the direction of initial rotation, a torsionally resilient link connecting said rotor to said inertia device and normally maintaining opposed oscillatory movement of said device and rotor when said field winding alone is energized for driving said device, means for closing a circuit to said field winding, and means energized by the closing of said circuit independent of motor rotation to momentarily close a circuit through said starting Winding to momentarily create a starting torque in one direction, said last-named means comprising a solenoid having a plunger, and contacts in said circuit, and means carried by said plunger for closing said contacts by movement of said plunger.

9. In an oscillating drive, a rotatable device having inertia resistance to rotation, an induction motor having a field winding, a starting winding, and a rotor, the latter rotatable in either direction with substantially equal torques for any given speed when said field winding only is energized, and unequal torques biased in one direction when said field winding and starting winding are both energized depending on the direction of initial rotation, a torsionally resilient link connecting said rotor to said inertia device and normally maintaining opposed oscillatory movement of said device and rotor when said field winding alone is energized for driving said device, means for establishing oscillatory movement of said rotor by energization of said field winding and initial momentary energization of said starting winding, means associated with said rotor adapted to close a circuit upon rotation of said rotor in one direction only, and open and hold said circuit open upon reverse rotation, and means for causing said rotor to discontinue oscillatory motion and commence continuous rotation comprising means to energize said starting winding through said circuit.

10. In an oscillating drive, a rotatable device having inertia resistance to rotation, an induction motor having a field winding, a starting winding, and a rotor, the latter rotatable in either direction with substantially equal torques for any given speed when said field winding only is energized, the direction of rotation depending on the direction of initial rotation, a torsionally resilient link connecting said rotor to said inertia device for driving said device, means for energizing said field winding and momentarily said starting winding adapted to initiate rotation of said rotor in one direction, switch means associated with said rotor, adapted to open during rotation in said one direction and close during rotation in the other direction, and means for placing said switch means in circuit with said starting winding to energize said starting winding during all rotation in one direction to cause said rotor to discontinue oscillatory rotation and commence continuous rotation.

11. In an oscillating drive, a rotatable device having inertia resistance to rotation, an induction motor having a field winding, a starting winding, either direction with substantially equal torques for any given speed when said field winding only is energized, the direction of rotation depending on the direction of initial rotation, a torsionally resilient link connecting said rotor to said inertia device for driving said device, means for energizing said field winding and momentarily said starting winding adapted to initiate rotation of said rotor in one direction, switch means associated with said rotor, adapted to open during rotation in said one direction and close during rotation in the other direction, and means for placing said switch means in circuit with said starting winding to energize said starting winding during all rotation in one direction to cause said rotor to discontinue oscillatory rotation and commerce continuous rotation, said switch means opening during rotation in the direction of ultimate continuous rotation, whereby said starting winding when energized resists rotation in a direction opposite to ultimate rotation, and remains open once continuous rotation is established.

EARL C. WILLIAMS.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,230,345 Bradbury Feb. 4, 1941 2,296,263 Breckenridge 1 Sept. 22, 1942 2,313,984 Breckenridge et al. Mar. 16, 1943 2,355,162 Hovey Aug. 8, 1944 2,411,960 Dyer Dec. 3, 1946 2,430,668 Chamberlin Nov. 11, 1947 2,517,038 Dayton Aug. 1, 1950 2,580,963 Sisson Jan, 1, 1952 2,588,963 Chapin Mar. 11, 1952 and a rotor, the latter rotatable in 

